Ehgoetz Martens K A, Ellard C G, Almeida Q J
Sun Life Financial Movement Disorders Research and Rehabilitation Centre, Wilfrid Laurier University, 75 University Avenue West, Waterloo, Ontario N2L 3C5, Canada; Department of Psychology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Department of Psychology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Neuroscience. 2014 Aug 22;274:162-9. doi: 10.1016/j.neuroscience.2014.05.022. Epub 2014 May 21.
Parkinson's disease patients who suffer from freezing of gait (PD-FOG) may have sensory and/or perceptual deficits, although they are difficult to disentangle. This study evaluated whether visuospatial perception or self-motion perception were more impaired in PD-FOG, and whether distance estimation errors might be related to misperception of physical walking (compared to imagined). Finally, cognitive status was evaluated in order to evaluate whether cognitive status predicts any of the perception deficits identified. Nine PD-FOG and 15 PD-nonFOG were tested. In experiment 1, participants were shown a target, then the target was removed, before participants demonstrated the original position of the target in two different feedback conditions (pointing with a laser, or walking to its original position). In experiment 2, participants walked to a target (3, 4.5, 6m) and then imagined walking to that same target. The time to complete both of these tasks was measured and compared. Experiment 1 found a significantly greater judgment error in PD-FOG across both conditions (p=0.013) (compared to PD-nonFOG). Constant error revealed that both groups significantly underestimated during the self-motion condition only (p=0.01). Interestingly, results from experiment 2 demonstrated a significant discrepancy between the time it took to imagine walking compared to their actual movement times, specifically in PD-FOG (p=0.03). This mismatch as well as cognitive status significantly predicted judgment errors during the self-motion condition from experiment 1. Therefore, this study found evidence that PD-FOG have significantly greater sensory-perception deficits compared to PD-nonFOG. These findings have important clinical implications for further understanding FOG and developing new rehabilitative strategies for FOG symptoms.
患有冻结步态的帕金森病患者（PD - FOG）可能存在感觉和/或感知缺陷，尽管这些缺陷难以区分。本研究评估了在PD - FOG中视觉空间感知或自我运动感知是否受损更严重，以及距离估计误差是否可能与对实际行走（与想象行走相比）的感知错误有关。最后，对认知状态进行评估，以确定认知状态是否能预测所发现的任何感知缺陷。对9名PD - FOG患者和15名非PD - FOG患者进行了测试。在实验1中，向参与者展示一个目标，然后移除目标，之后参与者在两种不同的反馈条件下（用激光指示或走到其原始位置）展示目标的原始位置。在实验2中，参与者走到一个目标（3米、4.5米、6米），然后想象走到同一个目标。测量并比较完成这两项任务的时间。实验1发现，在两种条件下，PD - FOG的判断误差均显著更大（p = 0.013）（与非PD - FOG相比）。恒定误差表明，两组仅在自我运动条件下均显著低估（p = 0.01）。有趣的是，实验2的结果表明，想象行走所需时间与实际运动时间之间存在显著差异，特别是在PD - FOG中（p = 0.03）。这种不匹配以及认知状态显著预测了实验1中自我运动条件下的判断误差。因此，本研究发现有证据表明与非PD - FOG相比，PD - FOG存在明显更大的感觉 - 感知缺陷。这些发现对于进一步理解冻结步态以及开发针对冻结步态症状的新康复策略具有重要的临床意义。
